Rocker arms for vehicle engines are typically challenging to manufacture because they require a structurally sound tubular portion extending laterally through the part.
The prior art provides many methods of manufacturing rocker arms. One method is to stamp the part and drill a main aperture through the part. A tube is then inserted into the aperture to form the structurally sound tubular portion extending through the rocker arm and to provide structural integrity to the assembly. The assembly is then subject to brazing and honing operations. This method is not particularly efficient because the inserted tube results in added cost and manufacturing time.
Another example of a prior art rocker arm manufacturing process includes casting the entire rocker arm with the central tube formed integrally therewith. This method requires expensive secondary machining operations. It also requires cross ribs for added strength.
Accordingly, it is desirable to provide an improved method of manufacturing a workpiece, such as a rocker arm, with a structurally sound tubular portion extending through the part. It is also desirable to provide an improved rocker arm design in which manufacturing costs are reduced, and structural integrity is not compromised.